Dove tail modulator for condenser

ABSTRACT

A vehicle air conditioning system has a condenser with a header tank attached to it. A modulator attaches to the header tank using a full-length dove tail joint that is further secured and sealed to the header tank by a brazing process. A modulator inlet receives gaseous refrigerant from the condenser and discharges liquid refrigerant to a bottom, sub cooler portion of the condenser. The modulator inlet and outlet pass through the dove tail joint of the modulator and header tank.

FIELD

The present disclosure relates to a condenser for a vehicle air conditioner, and more specifically, to an attachment mechanism for attaching a modulator to a condenser header tank.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. Vehicle air conditioning systems commonly employ a condenser that operates in conjunction with a modulator, also known as a receiver or dryer. The condenser cools the high-temperature, high-pressure gas refrigerant sent from a compressor, and condenses it into a liquid refrigerant. The modulator begins separating the gas and liquid refrigerants and sends the primarily liquid refrigerant into a subcooler, which may be located in a bottom portion of the same condenser. In some condenser-modulator arrangements, the modulator is attached to the condenser. While such attachment structures of modulators to condensers have proven satisfactory for their purposes, each is not without its share of limitations.

One such limitation of a current condenser and modulator attachment structure is that flat surfaces found on each of the condenser and modulator requires an intermediate plate to be positioned to braze the flat surfaces together in order to joint them. Another limitation pertains to affixing the intermediate plate, which requires the plate to be crimped or caulked to the modulator and the header tank before brazing. Furthermore, brazing only occurs at the intermediate plate, and not along an extended length of the modulator and header tank.

To best illustrate the shortcomings of the prior art, FIG. 6 depicts a cross-sectional view of the prior art modulator with its flat surface 11 for connection while FIG. 7 depicts a modulator 10, to which a modulator plate 12 is attached. More specifically, the modulator plate 12 attaches to a flat surface 14 of the modulator 10 with a number of tabs on the modulator plate 12.

Center tabs 18 are used to attach the modulator plate 12 to the modulator 10, while corner tabs 16 are used to attach the modulator plate 12 to the header tank 20. FIG. 8 depicts the attachment of the modulator plate 12 to the modulator 10 and the header tank 20. After the tabs 16, 18 are crimped, a brazing process secures the modulator plate 12 to the modulator 10 and the header tank 20. Before the brazing process, careful manipulation of the modulator plate 12, modulator 10, and header tank 20 is required to ensure proper alignment before crimping. The modulator plate 12 remains between the modulator 10 and the header tank 20 after brazing.

What is needed then is a device that does not suffer from the above limitations. This, in turn, will provide a device such that: a modulator is connectable to a header tank along an entire length of the modulator; no intermediate plate is necessary between the modulator and header tank to facilitate joining; no crimping or bending of such an intermediate plate is necessary to join the modulator to the header tank; and no special care is necessarily needed to align the modulator and header tank before brazing.

SUMMARY

A vehicle air conditioning system has a condenser with a header tank attached to it. A modulator attaches to the header tank using a full-length dove tail joint that is further secured and sealed to the header tank by a brazing process. One configuration of the dove tail joint is to place the recessed dove tail portion in the modulator with the corresponding, protruding dove tail that secures into the recessed portion, in the header tank. A modulator inlet receives gaseous refrigerant from the condenser and discharges liquid refrigerant to a bottom, sub cooler portion of the condenser. The modulator inlet and outlet pass through the dove tail joint of the modulator and header tank.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1 is a side view of a vehicle depicting the location of an engine within which a condenser resides, according to the present invention;

FIG. 2 is a diagram of a vehicle air conditioning system, depicting the location of a condenser, according to the present invention;

FIG. 3 is a front view of a condenser depicting a modulator;

FIG. 4 is a cross-sectional view of a modulator with a dove tail connection, according to the present invention;

FIG. 5 is a perspective view of a modulator attached to a header tank in accordance with the present invention;

FIG. 6 is a cross-sectional view of a modulator with a flat surface connection, according to the prior art;

FIG. 7 is a perspective view of a modulator and a modulator plate, according to the prior art; and

FIG. 8 is a perspective view of a modulator and a header tank connected with a modulator plate, according to the prior art.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

In accordance with FIGS. 1-5, details of the present invention will be explained; turning to FIG. 1, a vehicle 100 is depicted with an engine 102 shown in phantom. In accordance with FIG. 2, the engine 102 drives an HVAC system 104, depicted as a block diagram. A refrigeration cycle R of the vehicle HVAC system 104 includes an air-conditioning or air-cooling system 106. The air-cooling system 106 includes a compressor 108 that draws, compresses, and discharges a refrigerant. The power output of the vehicle engine 102 is transmitted to the compressor 108 through a pulley 110 and a belt 112. As is well known, the vehicle engine 102 drives not only the air conditioning compressor 108 but also such auxiliary components such as a generator, a hydraulic pump for a power steering unit, and a coolant pump via belts and other power transmitting devices.

In the refrigeration cycle R, the compressor 108 discharges a superheated gaseous refrigerant of high temperature and high pressure, which flows into a condenser 114. In the condenser 114, heat exchange is performed with the outside air propelled by a cooling fan 116, so that the refrigerant is cooled for condensing within the condenser 114. The refrigerant condensed in the condenser 114 then flows into a modulator 118, also known as a receiver or dryer, in which the refrigerant is separated into a gas and a liquid. A redundant liquid refrigerant in the refrigeration cycle R is stored inside the modulator 118.

The liquid refrigerant from the modulator 118 is decompressed by an expansion valve 120 into a gas-liquid double phase state of low pressure refrigerant. The low pressure refrigerant from the expansion valve 120 flows into an evaporator 122 by way of an inlet pipe 124. The evaporator 122 is arranged inside an HVAC case 126 of the vehicle air conditioning system 106. The low pressure refrigerant flowing into the evaporator 122 absorbs heat from the air inside the HVAC case 126 for evaporation. An outlet pipe 128 of the evaporator 122 is connected to the suction side of the compressor 108, so that the cycle components mentioned above constitute a closed circuit.

The HVAC case 126 forms a ventilation duct through which air conditioning air is sent into the passenger compartment 130. The HVAC case 126 contains a fan 132 that is arranged on the upstream side of the evaporator 122. An inside/outside air switch box (not shown) is arranged on the suction side of the fan 132 (the left side in FIG. 2). The air inside the passenger compartment (inside air) or the air outside the passenger compartment (outside air) switched and introduced through the inside/outside air switch box is sent into the HVAC case 126 by the fan 132.

The HVAC case 126 accommodates, on the downstream side of the evaporator 122, a hot water heater core (heat exchanger) 134. The heater core 134 includes an inlet pipe 136 and an outlet pipe 138. Hot water (coolant) of the vehicle engine 102 is directed to the heater core 134 through the inlet pipe 136 by a water pump 140. A water valve 142 controls the flow volume of engine coolant supplied to the heater core 134. A radiator 144 and a thermistor 146 further cooperate to control the temperature of the coolant.

A bypass channel 148 is formed beside the hot water heater core 134. An air mix door 150 is provided to adjust the volume ratio between warm air and cool air that passes through the hot water heater core 134 and the bypass channel 148, respectively. The air mix door 150 adjusts the temperature of the air blown into the passenger compartment 130 by adjusting the volume ratio between the warm air and cool air.

Additionally, a face outlet 152, a foot outlet 154, and a defroster outlet 156 are formed at the downstream end of the HVAC case 126. The face outlet 152 directs air toward the upper body portions of passengers, the foot outlet 154 directs air toward the lower extremities of the passengers, and the defroster outlet 156 directs air toward the internal surface of a vehicle windshield. The outlets 152, 154 and 156 are opened and closed by outlet mode doors (not shown). The air mix door 150 and the outlet mode doors mentioned above are driven by electric driving devices such as servo motors via linkages or the like.

With further reference now to FIGS. 3-5, a dove tail joint and its application as a modulator and head tank connection joint will be explained in accordance with the present invention. FIG. 3 is generally a front view of a condenser 114 and an attached modulator 118. More specifically, the modulator 118 attaches to the left header tank 158, which is referred to in such a way because it is on the left side of the condenser 114 in FIG. 3. A right header tank 160 resides on the right side of the condenser 114, opposite the left header tank 158. During operation of the HVAC system 104, gaseous refrigerant enters the right header tank 160 at the condenser inlet 162 after being compressed by the compressor 108. The gaseous refrigerant passes out of the right header tank 160 and into multiple tubes 164 en route to the left header tank 158. While passing through the tubes 164, the gaseous refrigerant is cooled as heat from the compressed refrigerant passes from the tubes 164 into fins 166 that join the parallel tubes 164. The fins 166 permit air currents generated by the fan 116 to pass around the condenser tubes 164 and fins 166 and remove heat from the gaseous refrigerant.

After passing from the tubes 164 of the upper condenser portion 168 of the condenser 114, the refrigerant passes into a top compartment 186 of the left header tank 158 and then into the modulator 118, which removes moisture from the refrigerant. More specifically, the modulator 118 receives the gaseous and liquid refrigerant through a first modulator port or hole 182 and then discharges liquid refrigerant through a second modulator port or hole 184. The header tank 158 has corresponding holes to facilitate the refrigerant transfer. In the modulator 118 the gaseous refrigerant 170 continues to condense into liquid refrigerant 172. The liquid refrigerant 172 then passes from the modulator 118 back into a bottom compartment 188 of the left header tank 158 before passing into a lower subcooler portion 178 of the condenser 114. Generally, the upper condenser portion 168 and subcooler portion 178 together form the core of the condenser 114. Upon exiting the subcooler portion 178 and passing into the right header tank 160, the liquid refrigerant passes from the condenser at a condenser outlet 180. Because the left header tank 158 is divided into an upper compartment 186 and a lower compartment 188, the upper compartment 186 discharges the liquid and gaseous refrigerant into the modulator 118, while the lower compartment 188 receives mostly liquid refrigerant from the modulator 118. Similarly, because the right header tank 160 is also divided into an upper compartment 190 and a lower compartment 192, the upper compartment 190 receives gaseous refrigerant before cooling and condensing, while the lower compartment 192 receives liquid refrigerant from the subcooler portion 178 after cooling and condensing.

Regarding more specific details of the invention, the joining of the modulator 118 to the left header tank 158 will now be discussed. FIG. 4 depicts a modulator 118 with a dove tail recession 194 within a mounting bracket 196. The modulator 118, mounting bracket 196 and dove tail recession 194 are, in one instance, a single piece of extruded aluminum. By forming the modulator 118 as a single extrusion, part count is reduced while part rigidity and structural integrity are ensured. FIG. 5 depicts the modulator 118 joined to the header tank 158 at joint 159. More specifically, the header tank 158 has a dove tail projection 198 that resides within the dove tail recession 194 of the modulator 118 to form the joint 159. Similarly to the modulator 118, in one example the header tank 158 may be formed as a single extruded aluminum part. By forming the header tank 158 as a single extrusion, part count is reduced while part rigidity and structural integrity are ensured. To join the modulator 118 to the header tank 158, as depicted by joint 159, the recession 194 of the modulator 118 is simply slid around the dove tail projection 198 of the header tank 158. Alternatively, the projection 198 of the header tank is slid within and along the recession 194. The joint 159 is formed beginning with one end of each part and as the parts are slid together, thus forming the interlocking dove tail joint, the joint 159 is furthered until completed. The modulator 118 may have its dove tail component formed along the entire length of the modulator 118, as opposed only to a portion or portions of the modulator's length. Depicted in FIG. 3, the ports 182, 184 pass through the dove tail joint 159.

Because the modulator 118 is brazed to the header tank 158, before beginning the mechanical dove tail connection, a brazing compound is placed on either the dove tail recession 194 of the modulator 118 or the dove tail projection 198 of the header tank 158. Upon successfully completing the mechanical, dove tail joining of the modulator 118 to the header tank 158, the parts may then be brazed together in a brazing process, such as in a brazing furnace. In such brazing process in accordance with the aluminum part examples provided, the melting point of the brazing alloy is lower than the aluminum modulator and aluminum header tank. The dove tail joint 159 is designed such that proper capillarity of the braze metal is facilitated to provide proper strength between the brazed modulator and header tank. The dove tail joint 159 of FIG. 3 is also representative of a brazed connection.

While the above description and FIG. 5 refer to and depict a dove tail projection 198 on the header tank 158 and a dove tail recession 194 on the modulator 118, the reverse is possible. That is, the modulator 118 may fashion a dove tail projection while the header tank 158 may fashion a corresponding dove tail recession. Connection of the reverse components would be similar to the above. Regardless of how the dove tail joint is configured, the dove tail joint permits rapid mechanical connection of the header tank and modulator without any special aligning of parts and subsequent crimping or caulking, as was required in the prior art.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. 

1. A condenser for an air conditioner comprising: a condenser; a modulator; and a header tank, wherein the modulator and condenser are joined together by a dove tail joint.
 2. The condenser of claim 1, wherein the dove tail joint is approximately the length of the modulator.
 3. The condenser of claim 1, further comprising: a subcooler portion, to receive liquid refrigerant from the modulator.
 4. The condenser of claim 3, the modulator further comprising: a refrigerant inlet port; and a refrigerant outlet port, wherein the inlet and outlet ports facilitate passage of refrigerant between the condenser core and the subcooler portion.
 5. The condenser of claim 1, wherein the dove tail joint is brazed.
 6. An air conditioning condenser for a vehicle comprising: a condenser core; a header tank: a modulator; and a dove tail joint, wherein the modulator and the header tank are joined together by the dove tail joint.
 7. The condenser of claim 6, wherein the dove tail joint is approximately the length of the modulator.
 8. The condenser of claim 6, wherein the modulator further comprises: a subcooler portion that receives liquid refrigerant from the modulator.
 9. The condenser of claim 6, further comprising: a modulator inlet port; and a modulator outlet port, wherein the modulator inlet and outlet ports provide a refrigerant path through the dove tail joint.
 10. The condenser of claim 9, further comprising: brazing along the length of the dove tail joint.
 11. An air conditioning condenser for a vehicle comprising: a condenser core; a header tank: a modulator defining a modulator inlet port and a modulator outlet port, wherein the modulator inlet and outlet ports provide a gaseous and liquid path between the header tank and the modulator; and a dove tail joint, wherein the modulator and the header tank are joined together by the dove tail joint that is approximately the length of the modulator.
 12. The condenser of claim 11, wherein the dove tail joint further comprises: a dove tail projection on the header tank; and a dove tail recession on the modulator.
 13. The condenser of claim 11, wherein the modulator inlet and outlet ports pass through the dove tail joint.
 14. The condenser of claim 13, wherein the modulator further comprises: a subcooler portion that receives liquid refrigerant from the modulator outlet port.
 15. The condenser of claim 9, further comprising: a braze connection along the length of the dove tail joint.
 16. The condenser of claim 11, wherein the dove tail joint further comprises: a dove tail projection from the header tank that is part of the header tank extrusion; and a dove tail recession in the modulator that is part of the modulator extrusion.
 17. The condenser of claim 11, wherein the dove tail joint further comprises: a dove tail recession in the header tank that is part of the header tank extrusion; and a dove tail projection from the modulator that is part of the modulator extrusion. 